Security fix: Markdown parsing vulnerability (PR #808)

Release Notes

Summary

This update addresses a security vulnerability in Markdown document
processing used by the security questionnaire service. Malformed Markdown
content could previously cause the service to crash when parsing
documents.

Changes

• Upgraded the Markdown processing library to a patched version that
  fixes CVE-2025-69534.
• Hardened document parsing so malformed Markdown input no longer
  causes an unhandled error and service interruption.
• Applies to knowledge base indexing and document parsing workflows
  that process Markdown content.

Impact

Security/audit impact: Reduces risk of denial-of-service from
malformed Markdown content submitted to document processing workflows.
No customer action required.

Classification

Security